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Cementing Tanks.
ON many grazing farms where there is
no natural water supply, or where
the supply is not permanent, its neces- <*>
sary to conserve large quantities of water
t? tide over a dry time. Tanks may be
filled by drainage, by pumping i'ro'u
natural sources when available or by catch*
ing the rainfall from any buildings in ti:o
vicinity and leading it by pipe* to the
tanks. In this way valuable reserves can
be secured for a homestead. Tanks
scooped out of the ground have the dis
advantage that they lose a large proportion
of water by soakage or leakage through
holes bored in the bottom by crayfish or
"yabbies," which in some areas make it
impossible to rctaiu the water in dams
and tanks. Surface tanks of galvanised
iron, holding from 20,000 to 30,000 ; ;alioi,a
each, have become common. But untor*
tuuately the "life" of a galvanised iron
tank is short, the metal perishing in a
few years. It is not generally known that
leaky tanks can be turned into permanent
storage units by coating them with vemeat
composition, thus making them practically
everlasting. The operation is not a very
difficult one for a careful man who haa
some knowledge of the properties ot
cement concrete. Even a novice con riak.i
a very fair job with care. If the tank
to be concreted is in a somewhat dilapid
ated condition, and out of shape, the first
step is to get the sides as nearly erect a*
possible, if necessary bracing them by
winding two or three turns of fencing wiro
near top and bottom, and straining them
up tight. A few strong stakes set deeply
in the ground and leaning inward a itt!e
83 as to touch the tank round the top
edge will also help to make it secure.
TJEFORE cementing, wire netting of
•^ about 2in. mesh is placed lound the
inside of the tank and fastened at fre
quent intervals by tie wires passed through
holes knocked in the iron of the lank from
the outside. These should be close enough
together to insure that the netting do-:?
not bulge, and is kept within, say, an inch
of the sides all round. The bottom should
be treated in the.same way. For the con
crete one part of cement is mixed with
three parts of clean sand, free front
stones. The sand and cement should be
well mixed, with a shovel dry, tu?a
sprinkled with water 'and turned over and
ovei again with the shovel until an even,
sloppy mixture is obtained. With tliM
mixture the bottom of the tank i« coated
to a thickness of 2in. (3in. is better if
economy is not an object), smoothing the
surface with a trowel or a piece of roaid.
To make a nice level job lay two pieca
of 2in. timber on the toundntion and fill
in the concrete level with these, scraping
the surface off evenly by means of a
straight edge renting on the 2in. piecei
and drawn along them. The 2in. timber
is removed afterwards, and the gups left
filled in with the cement mixture. Vhcu
the bottom is net the sides may be <oatc.fl,
the same mixture being used, although
it may be a little less sloppy, as it has
fc) be laid on with the trowel, working
the mixture well into the meshes of tue
wire netting, aud Juto the corrugations of
the tank. The composition should wcil
cover the netting, and the surface should
be smoothed with the trowel as the woik
proceeds. This will make a strong tad;
which will last for many years. If the
outside of the tank is coated in the same
manner it will make a much sounder job.
If the tank has not many rust nules in it
when the work is started it is advisable
to punch a number of holes ill the rou
from the outside, using a large nail or the
sharp point of a pick for the purpo?e.
This has the effect of "keying" the con*
cietc and holding it more firmly. As to
the material required, six casks of cement
and three times that quantity of sai.ii
will be sufficient to do a 15,000-galiou tai k
iuside.
$